       (trace 'gtm_tape1
              (-> state
                  (assoc-in [:gtm :secondary] (:primary (:gtm state)))
-                 (assoc-in [:gtm :primary 1])))
+                 (assoc-in [:gtm :primary] 1)))
       state)))
 
 (define-registered ;; set primary to tape2, secondary to prior primary

          state))
      state)))

(define-registered ;; push primary tape's instruction to code stack
  gtm_instruction
  ^{:stack-types [:gtm :code]}

      (trace 'gtm_tape0
             (-> state
                 (assoc-in [:gtm :secondary] (:primary (:gtm state)))
                 (assoc-in [:gtm :primary] 0)))
      state)))

(define-registered ;; set primary to tape1, secondary to prior primary
